Major depression is one of the most common psychiatric disorders to afflict adolescents, shows a recurrent course, and results in serious psychosocial impairment. Because most depressed youth never receive treatment, it is crucial to develop prevention programs for this disorder that can be easily disseminated. Surprisingly few depression prevention programs for adolescents have been evaluated in randomized trials and many have not produced significant intervention effects. The proposed project is a large-scale randomized trial of a brief 6- session cognitive-behavioral (CBT) depression prevention program for high-risk adolescents with subdiagnostic depressive symptoms. This intervention focuses on reducing negative cognitions and increasing engagement in pleasant activities, and utilizes motivational interviewing, strategic self-presentation, between-session homework, and relapse prevention. A 4-session version of this intervention resulted in significant reductions in depressive symptoms and risk for future onset of severe depressive pathology over a 6-month follow-up in a randomized pilot trial (N = 126). It was encouraging that the effects for this brief intervention were comparable to those for more intensive 8 to 15 session interventions. [unreadable] [unreadable] The proposed trial will randomly assign 300 high-risk adolescents (aged 14 - 16) who report subdiagnostic depressive symptoms in a 2-stage screening procedure to the 6-session CBT intervention or a monitored control condition and will follow them over a 2-year period with surveys and psychiatric interviews completed by participants and parents. We will test whether (1) there are greater reductions in depressive symptoms and risk for subsequent onset of major depression and dysthymia in the CBT condition than in the control condition; (2) intervention effects are mediated by changes in negative cognitions, frequency of pleasant activities, and nonspecific factors; (3) certain factors potentiate (e.g., elevated verbal intelligence and motivation) or mitigate (e.g., elevated negative life events and psychiatric comorbidity) intervention effects; and (4) there are greater improvements in psychosocialfunctioning, comorbid psychopathology, and mental health service utilization, in the CBT condition than in the control condition. Thus, the proposed project should provide a rigorous evaluation of this promising brief prevention program and should advance knowledge regarding the prevention of this pernicious psychiatric problem. [unreadable] [unreadable]